scholarly journals Influence of Corophium volutator and Hydrobia ulvae on intertidal benthic diatom assemblages under different nutrient and temperature regimes

2002 ◽  
Vol 245 ◽  
pp. 47-59 ◽  
Author(s):  
SE Hagerthey ◽  
EC Defew ◽  
DM Paterson
Keyword(s):  
Benthic Diatom ◽  
Diatom Assemblages ◽  
Corophium Volutator ◽  
Hydrobia Ulvae ◽  
Temperature Regimes

Paleodepth determination from Antarctic benthic diatom assemblages

1997 ◽  
Vol 29 (3-4) ◽  
pp. 301-318 ◽  
Author(s):  
Jason M. Whitehead ◽  
Andrew McMinn
Keyword(s):  
Benthic Diatom ◽  
Diatom Assemblages

scholarly journals Differential photosynthetic responses of marine planktonic and benthic diatoms to ultraviolet radiation under various temperature regimes

2017 ◽  
Vol 14 (22) ◽  
pp. 5029-5037 ◽  
Author(s):  
Yaping Wu ◽  
Furong Yue ◽  
Juntian Xu ◽  
John Beardall
Keyword(s):  
Ultraviolet Radiation ◽  
Uv Radiation ◽  
Benthic Diatom ◽  
Extreme Temperatures ◽  
Benthic Species ◽  
Temperature Regimes ◽  
Photosynthetic Responses ◽  
Periodic Exposure ◽  
Damage Processes ◽  
Planktonic Species

Abstract. We studied the photophysiological responses to ultraviolet radiation (UVR) of two diatoms, isolated from different environmental niches. Both species showed the highest sensitivity to UV radiation under relatively low temperature, while they were less inhibited under moderately increased temperature. Under the highest temperature applied in this study, the benthic diatom Nitzschia sp. showed minimal sensitivity to UV radiation, while inhibition of the planktonic species, Skeletonema sp., increased further compared with that at the growth temperature. These photochemical responses were linked to values for the repair and damage processes within the cell; higher damage rates and lower repair rates were observed for Skeletonema sp. under suboptimal temperature, while for Nitzschia sp., repair rates increased and damage rates were stable within the applied temperature range. Our results suggested that the response of the microalgae to UV radiation correlated with their niche environments, the periodic exposure to extreme temperatures promoting the resistance of the benthic species to the combination of high temperature and UV radiation.

Effects of Didymosphenia geminata blooms on benthic diatom assemblages in the Restigouche River Watershed, eastern Canada

Botany ◽  
2015 ◽  
Vol 93 (5) ◽  
pp. 317-323 ◽  
Author(s):  
Branaavan Sivarajah ◽  
Joshua Kurek ◽  
Kathleen M. Rühland ◽  
John P. Smol
Keyword(s):  
Benthic Diatom ◽  
Diatom Assemblage ◽  
Diatom Assemblages ◽  
Eastern Canada ◽  
Didymosphenia Geminata ◽  
Assemblage Composition ◽  
River Watershed ◽  
And Function ◽  
Riverine Systems ◽  
The Impact

Nuisance Didymosphenia geminata (Lyngbye) M. Schmidt (didymo) blooms were first reported in 2006 from the Restigouche River Watershed (RRW), eastern Canada. Although government agencies and recreational users are concerned about these blooms, little is known about the impact on biota and (or) the structure and function of the relatively pristine riverine systems of the RRW. Here, we assess whether didymo blooms affect overall benthic diatom assemblage composition by examining epilithic samples from middle stretches of the Patapedia and Upsalquitch rivers. Significant (albeit minor) differences (P < 0.05) in diatom assemblage composition between sites, with and without didymo blooms, were only observed from the Patapedia River. Rarefied diatom species diversity (Hill’s N2) and rarefied richness did not differ significantly among sites, regardless of the presence or absence of blooms. Our data show that didymo blooms have minimal effect on benthic diatom assemblage composition in the RRW.

Penicillin-mediated changes in viable benthic diatom assemblages – insights about the relevance of bacteria across spatial and seasonal scales

2014 ◽  
Vol 65 (5) ◽  
pp. 437 ◽  
Author(s):  
Priya M. D'Costa ◽  
Arga C. Anil
Keyword(s):  
Ecological Study ◽  
Benthic Diatom ◽  
Diatom Assemblages ◽  
Total Inhibition ◽  
Mesocosm Experiments ◽  
Lactam Antibiotic ◽  
Intertidal Sandflat ◽  
Penicillin Treatment ◽  
Conditioning Film ◽  
Limited Diffusion

Penicillin, a β-lactam antibiotic, cannot affect diatoms directly but does so through bacteria. Its effects on viable benthic diatom assemblages in a tropical environment were evaluated across spatial (intertidal sandflat, mangrove site, port environment) and seasonal (post-monsoon, pre-monsoon, monsoon) scales. Penicillin treatment resulted in bacterial suppression and a reduction in diatoms at the intertidal and mangrove sites having stable pennate-dominated assemblages. Diatom response at the port site, dominated by transient centric diatoms, ranged from total inhibition to enhancement. The monsoon diatom assemblages, which differed in composition from those in other seasons, showed reduced susceptibility to penicillin. These observations highlight the bacterial influence on diatom assemblages and the significance of species composition of diatom assemblages in these interactions. Epipsammic diatoms (Cocconeis, Grammatophora and Thalassionema) were more sensitive to penicillin than epipelic forms, probably due to: (1) their inability to escape unfavourable bacterial metabolites because of limited diffusion in benthic environments; and (2) the interference of penicillin with the bacterial ‘conditioning’ film required for their attachment. Overall, the observations from the present, preliminary, ecological study provide insights into the relevance of bacteria in influencing viable benthic diatom assemblages across spatial and seasonal scales and emphasise the need for future mesocosm experiments on these aspects.

How do abiotic environmental variables shape benthic diatom assemblages in subtropical streams?

2017 ◽  
Vol 68 (5) ◽  
pp. 863 ◽  
Author(s):  
Wing Ying Tsoi ◽  
Wade L. Hadwen ◽  
F. Sheldon
Keyword(s):  
Environmental Gradients ◽  
Critical Role ◽  
Benthic Diatom ◽  
Base Flow ◽  
Diatom Assemblage ◽  
Environmental Drivers ◽  
Diatom Assemblages ◽  
Physical And Chemical Variables ◽  
Ecological Importance ◽  
Physical And Chemical

Diatoms (Division Bacillariophyta) commonly dominate benthic algal communities in upland streams and are the major primary producers that sit at the base of food webs. Given their ecological importance, the aim of the present study was to investigate the spatial patterns of freshwater biofilm biomass and diatom assemblage composition in response to differences in physical and chemical variables in the Bremer, Logan and Albert catchments in south-east Queensland. Patterns in benthic diatom assemblage structure were examined during base flow conditions and the focus was on relating the spatial hierarchical interrelationships among ultimate (i.e. catchments and geology) and proximate (i.e. flow, nutrients, light, conductivity, pH and turbidity) environmental drivers. The spatial difference observed in the benthic diatom assemblages was predominantly driven by proximate environmental drivers, which, in turn, were affected by ultimate drivers. Flow played a critical role in controlling both biofilm biomass and affecting the occurrence of diatom taxa. Nutrients and light also played roles as limiting resources structuring biofilm biomass and the relative abundance of diatoms. Diatom growth form, cell size and attachment mode can be used to create a more quantitative and predictive approach to establishing relationships between diatoms and environmental gradients.

scholarly journals Using benthic diatom assemblages to assess sedimentary nutrient status in Tri An reservoir, Dong Nai province, Vietnam

2021 ◽  
Vol 5 (2) ◽  
pp. first
Author(s):  
Yến Thị Hoàng Trần ◽  
Thái Thành Trần ◽  
Quảng Xuân Ngô ◽  
Hà Mạnh Bùi ◽  
Lưu Thanh Phạm
Keyword(s):  
Sediment Quality ◽  
Nutrient Status ◽  
Biological Indicators ◽  
Underground Water ◽  
Benthic Diatom ◽  
Diatom Assemblages ◽  
Nutrient Contents ◽  
High Nutrient ◽  
Nutritional Compounds

Tri An Reservoir plays an important role in the water supply for Dong Nai province and Ho Chi Minh city. It also contributes significantly to increase underground water reserves in the vicinity, especially in the dry season. However, recently, the increase of nutritional compounds in the lake has contributed to eutrophication, causing serious deterioration of the quality of the environment, creating conditions for microalgae to thrive. Therefore, this study aimed to evaluate and zoning the sediment quality of the Tri An reservoir based on using benthic diatom communities as biological indicators as an indicator tool. Sediment and algae samples were collected from 8 survey locations in the Ho Tri An area from March to August in 2019. The results showed that the dominance of several species belonging to the genera that prefer to live in nutrient-rich environment such as Navicula, Nitzschia. The TDI index indicated the sediment environment had high nutrient contents. Water quality in the lower section of the reservoir was classified from eutrophic (even hyper-eutrophic) status, particularly stations into the reservoir. Meanwhile, upstream and downstream sites had lower nutrient levels, mainly excessive phosphorus but still in eutrophic class. Additionally, the initial analysis results also revealed that NH4 +, TN, PO4 3􀀀 and DO played a major role to regulate the development of benthic diatom assemblages.

Combined eco-morphological functional groups are reliable indicators of colonisation processes of benthic diatom assemblages in a lowland stream

2016 ◽  
Vol 64 ◽  
pp. 31-38 ◽  
Author(s):  
Viktória B-Béres ◽  
Áron Lukács ◽  
Péter Török ◽  
Zsuzsanna Kókai ◽  
Zoltán Novák ◽  
...  
Keyword(s):  
Functional Groups ◽  
Benthic Diatom ◽  
Diatom Assemblages ◽  
Lowland Stream
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